OPTIMIZE TABLE tbl_name
Kicks off a garbage collection pass over the specified tables to free up memory being stored in deleted rows or in rows from rolled back transactions. The garbage collector will be kicked off automatically by MemSQL whenever it believes enough garbage memory has accumulated in the table to be worth the cost of running the garbage collection, so this command isn’t needed in normal operation. The command exists to give some control over when a garbage collection pass may occur.
EXPLAIN SELECT select_options
Shows the indexes used and some hits about the query plan used. The output is in the same format as MySQL’s EXPLAIN functionality.
CHECK TABLE tbl_name [, tbl_name] ...
Shows some stats about each index in a given table.
KILL [CONNECTION | QUERY] thread_id
KILL CONNECTION kills the connection with the specified thread_id. Any query running on the connection will be rolled back. KILL QUERY kills a query running on the thread_id, but leaves the connection open. MemSQL checks for the kill bit during any potentially long running loop during query execution and rolls back the query’s transaction if the kill bit is set. Note that the thread_id can be found by running SHOW PROCESSLIST.